Recent development work by others has produced several dyeing procedures in which exceptionally short liquor ratios are successfully employed. In general, the short liquor ratios involved (i.e., ratio of substrate weight to weight of treating liquor) are of the order at which no liquor exists outside the substrate upon application of the treating liquor thereto, so that the dyeing system involved is essentially a non-migrating one.
In providing apparatus and operating practice for practical application of these dyeing procedures to piece goods it has been found that because of the exceptionally short liquor ratios employed any dyestuff losses occurring during processing are apt to be significant and need to be prevented. The present invention provides an improved apparatus and processing method by which such losses are effectively prevented and which have proven equally effective for other purposes with great flexibility as noted further below.